Bojagi is a game of visual reasoning and basic mathematics. Young students can use the game to practice their multiplication facts, and they can create their own levels to challenge their friends. Older students and adults can exercise their creativity by creating fiendishly difficult puzzles.
A bojagi is a Korean traditional wrapping cloth. They were often made by sewing pieces together like a patchwork quilt. I picked this name because the completed designs sometimes resemble a patchwork.
The game Rectangles by Simon Tatham is based on the same concept.